Weft thread cutter for looms



Sept. 17, 1957 ZAPF WEF T THREAD CUTTER FOR LOOMS Filed Sept. so. 1955' JNVENTUR.

United States Patent WEFT TH EAD CUTTER 'FOR IIOOMS Georg *Zapf, ISuchteln, Germany, ia'ssignor to' IFirma Vereinigte Se'idenwe'bereien A. (L, Krefeld, Germany, a corporation oftGermany Applicationseptember 30, 1955, Serial 'No. 537,762 llaims priority, application Germany fio'toher 23, 1 154 41Claims. (Cl. 139-266) The present invention relates :to weft thread cutters for looms.

:In order :to cut the end of the thread remaining on the weaving material at the occasion :of the weft change it is :known :to provide cutters on "the looms which are disposed in most instances at the selvage in connection with temples. These cutters :are operated by means of levers and springs continuously from the slay during the forward stop. Due to the continuous operation the sharpness of the cutter suffers and furthermore great wear on the pivot and on the wiper motion parts is experienced, thus requiring a comparatively frequent adjustment and repair.

It has been proposed before to provide the cutter with a iswingable ,presser'which is controlled by the box motion by .means of an electromagnet, which presser is brought into engaging position w'ith'the stop of the slay in order to provide mechanical operation of the cutter. In this case, however, the cutter must be in operation for such length of time until the threads to be cut enter the mouth of the cutting instrument due to the continuous weaving of the weaving material and are then cut. This arrangement requires the'provision of a time operated relay and causes comparatively high costs.

It is, therefore, one object of the present invention to provide weft thread cutters for looms in which the operation of the cutter is responsive to the entrance of the thread into the mouth of the cutting instrument, in order to arrive at an operation of the cutter which requires the least possible Working time.

It is another object of the present invention to provide weft thread cutters for looms which includes a cutter blade the operation of which is responsive to the entrance of the thread into the mouth of the cutting instrument.

It is still another object of the present invention to provide Weft thread cutters for looms the operation of which is responsive to the entrance of the thread into the cutter which control is brought about by the arrangement of a feeler which enters the mouth of the cutting instrument, which feeler controls the movement of a cutter blade by a swinging of the feeler caused by the thread.

It is yet another object of the present invention to provide Weft thread cutters for looms in which the drive for the cutter blade is achieved by any suitable means, preferably, however, by arranging a movable cutter blade opposite to an immovable cutter blade, which movable cutter blade is mounted on the anchor of an electromagnet the operating circuit of which is closed by the movement of the feeler.

It is also a further object of the present invention to provide weft thread cutters for looms which operates equally well with right and left running threads and in which the pile thread cutters are connected with temples, which end is achieved by forming the feeler as a fork and by arranging in the housing carrying the weft "ice '2 thread cutters .with cross channels open at both ends and adapted to receive the temples and their cover.

With these and other objects in view, which will become apparent in the following detailed description, the present invention will be clearly understood in connection with the accompanying drawing, in which:

Figure 1 is a front elevation of weft thread .cuttfils for looms with a housing therefor in connection with temples;

Fig. 2 is a section along the 1inesII-II wQf'Eig. :1; and

Fig. 3 is a section along the lines III-III of Fig. 2.

Referring now to the drawing, it will be apparent that the eye 2 of the housing is equipped with a set screw 1 and carries an anchor lever 4 at the end .o'fwhich a culter blade 5 is mounted. On the bearing plate ,5 which is disposedacross a housing 3 is secured ,ascarry'ing plate 7 which supports a block the latter forming together with .the side walls 10 of ;the bearing plate .6 the mouth opening '9 of'the cutter.

.A feeler 12 which is formed as .a fork 11 enters the mouth 9 of the .cutters, whereby .the points .of the :fork 11 enter grooves 13 worked into the block 8. The feeler 12 is equipped with a hub 14 for rotatable mounting thereof on the pin 15. The feeler ,12 is also equipped with one element 16 of a pair of contact terminals, the other element 17 of which is carried by .a tongue 18 mountedon the .member 19 of insulating material.

Two electromagnets 20 are providedon the carrying plate 17, "the poles of which electromagnets 20 are dis.- posed below the anchor lever 4. "The windings of the electromagnets 20 are connected over the conduit '21 with the tongue 18 and over the conduit 22 with a contact clamp 23 mounted on the member 19 of insulating material.

Furthermore, cross channels 24 and 25 are provided in the body of the bearing plate 6, which cross channels 24 and 25 are open at both ends and are adapted to receive the retaining bolt 26 of a roller temple 27 and of its cover 28.

The operation of the weft thread cutters is performed in the following manner:

After a weft change the ends of the thread of the old and of the new weft winding appears at the selvage adjacent each other. Due to the continued movement of the weaving material over the temples 27, the threads are fed into the mouth 9 of the cutters and swing the feeler 11, 12 backwardly, thereby bringing about an engagement between the contacts 16 and 17 and, thereby, the closing the circuit by grounding.

The terminal clamp 23 is preferably connected with a source of alternating current of usual frequency. Upon closing the circuit by grounding, the cutter blade 5 enters a reciprocating swinging movement, similar to that of an electrically operated bell, so that during said swinging movement the blade 5 engages the block 8. During this engagement the threads present on the block 8 are cut.

Due to the release of the yarn tension the feeler 11, 12 returns to its original position and disengages the contacts 16 and 17, whereby the cutter is rendered inoperative.

The return movement of the feeler 11, 12 may be achieved also by means of a spring 29, in which case the fork 11 engages abutment member 30.

The thread, under normal condition, is cut by merely a few movements of the cutter blade. The operating time required for such cutting is very short and is about of the order of a few one-tenths of a second. It is of advantage to accommodate the swinging frequency of the mass of the hammer to that of the alternating current,

Preferably a particularly suitable material, as for instance, silver, is used for the contacts 16 and 17.

Instead of providing a source of alternating current for the operation of the cutting device it is of course also possible to provide a, source of direct current in which case the anchor 4 is equipped with an interrupter in conventional manner in order to bring about the required swinging movement.

The cutting device may be arranged on the right as well as on the left side of the weaving material. In order to bring about such change it is merely necessary to mount the temples 27 and their cover 28 on the opposite side.

While I have disclosed one embodiment of the presentinvention, it is to be understood that this embodiment is given by way of example only and not in a limiting sense, the scope of the present invention being determined by the objects and the claims.

I claim:

1. A thread cutting mechanism for a weft replenishing loom in which a thread is moved forwardly on a weft replenishing operation of the loom, comprising a housing, a bearing plate disposed across said housing and having sidewalls, a carrying plate secured to said bearing plate, and a block supported by said carrying plate, said block together with said sidewalls of the bearing plate defining a cutter mouth, a cutter blade pivotally mounted in said housing, an electromagnetically operated device, said cutter blade being subjected to a swinging motion by said electromagnetically operated device, and feeler means straddling said cutter mouth and closing the circuit of said electromagnetically operated device responsive to the movement of said thread to be cut.

2. The thread cutting mechanism, as set forth in claim 1, in which said feeler means comprises a feeler member pivotally mounted on said bearing plate and straddles said cutter mouth, and said feeler member being moved by the said thread during the weft replenishing operation.

3. The thread cutting mechanism, as set forth in claim 2, in which said electromagnetically operated device is mounted on said bearing plate, and said cutter blade is secured to the anchor of the electromagnet of said device to be subjected to a reciprocating swinging movement upon closing the circuit of said electromagnet, and said feeler member has a first terminal contact, a second terminal contact provided on said bearing plate, said first and second terminal contacts engaging each other in the operative position of said feeler member, thereby closing the circuit of said electromagnet to start the cutting operation of said thread.

4. The thread cutting mechanism, as set forth in claim 3, in which said feeler member comprises a forked member and in which said bearing plate has crosswise disposed channels open at both ends and which includes a temple and a cover therefor, adapted to be mounted on said bearing plate and having projections complementary to and received by said channels on either side of said bearing plate.

References Cited in the file of this patent UNITED STATES PATENTS 

